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                    mountLazyComponent
            
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                    updateFunctionalComponent
            
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                    updateClassComponent
            
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                    updateHostRoot
            
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                    updateHostComponent
            
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                    updateHostText
            
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                <span>
            
                    
                    updateSuspenseComponent
            
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                    updatePortalComponent
            
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                    updateForwardRef
            
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                    updateFragment
            
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                    updateMode
            
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                <a href="../../flow/begin-work/update-profiler.html">
            
                    
                    updateProfiler
            
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                <a href="../../flow/begin-work/update-context-provider.html">
            
                    
                    updateContextProvider
            
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                    updateContextConsumer
            
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                    reconcileChildren
            
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                    调和列表
            
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                <span>
            
                    
                    commit 阶段
            
                </span>
            

            
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        <li class="chapter " data-level="1.5.1" data-path="../commit-root.html">
            
                <a href="../commit-root.html">
            
                    
                    commitRoot
            
                </a>
            

            
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        <li class="chapter " data-level="1.5.2" data-path="../invokeGuardedCallback.html">
            
                <a href="../invokeGuardedCallback.html">
            
                    
                    invokeGuardedCallback
            
                </a>
            

            
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        <li class="chapter " data-level="1.5.3" data-path="../commitBeforeMutationLifecycles.html">
            
                <a href="../commitBeforeMutationLifecycles.html">
            
                    
                    commitBeforeMutationLifecycles
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.5.4" data-path="../commit-all-host-effects.html">
            
                <a href="../commit-all-host-effects.html">
            
                    
                    commitAllHostEffects
            
                </a>
            

            
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        <li class="chapter active" data-level="1.5.4.1" data-path="CommitPlacement.html">
            
                <a href="CommitPlacement.html">
            
                    
                    commitPlacement
            
                </a>
            

            
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        <li class="chapter " data-level="1.5.4.2" data-path="CommitWork.html">
            
                <a href="CommitWork.html">
            
                    
                    commitWork
            
                </a>
            

            
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        <li class="chapter " data-level="1.5.4.3" data-path="CommitDeletion.html">
            
                <a href="CommitDeletion.html">
            
                    
                    commitDeletion
            
                </a>
            

            
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            </ul>
            
        </li>
    
        <li class="chapter " data-level="1.5.5" data-path="../commit-all-lifecycles.html">
            
                <a href="../commit-all-lifecycles.html">
            
                    
                    commitAllLifecycle
            
                </a>
            

            
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                    功能
            
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                                <div class="api-method"><div class="api-method-definition"><h1 id="commitplacement">commitPlacement</h1><p>&#x6302;&#x8F7D;&#x8282;&#x70B9;</p><h3 id="gethostparentfiber">getHostParentFiber</h3><pre><code class="lang-js"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">getHostParentFiber</span>(<span class="hljs-params">fiber: Fiber</span>): <span class="hljs-title">Fiber</span> </span>{
  <span class="hljs-keyword">let</span> parent = fiber.return
  <span class="hljs-keyword">while</span> (parent !== <span class="hljs-literal">null</span>) {
    <span class="hljs-keyword">if</span> (parent) {
      <span class="hljs-keyword">return</span> parent
    }
    parent = parent.return
  }
}

<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">isHostParent</span>(<span class="hljs-params">fiber: Fiber</span>): <span class="hljs-title">boolean</span> </span>{
  <span class="hljs-keyword">return</span> (
    fiber.tag === HostComponent ||
    fiber.tag === HostRoot ||
    fiber.tag === HostPortal
  )
}</code></pre>
<p>&#x5982;&#x4E0A;&#xFF0C;&#x5C31;&#x662F;&#x4ECE;&#x7236;&#x94FE;&#x4E0A;&#x627E;&#x5230;&#x7B2C;&#x4E00;&#x4E2A;&#x5177;&#x6709;<code>container</code>&#x7684;&#x8282;&#x70B9;&#x6216;&#x8005;&#x662F;<code>HostComponent</code></p><hr><p>&#x6839;&#x636E;&#x627E;&#x5230;&#x7684;<code>parent</code>&#x8BBE;&#x7F6E;&#x53D8;&#x91CF;</p><p>&#x5982;&#x679C;<code>parent</code>&#x9700;&#x8981;&#x91CD;&#x65B0;&#x8BBE;&#x7F6E;<code>text</code>&#x8C03;&#x7528;<code>resetTextContent</code></p><h3 id="gethostsibling">getHostSibling</h3><pre><code class="lang-js"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">getHostSibling</span>(<span class="hljs-params">fiber: Fiber</span>): ?<span class="hljs-title">Instance</span> </span>{
  <span class="hljs-keyword">let</span> node: Fiber = fiber
  siblings: <span class="hljs-keyword">while</span> (<span class="hljs-literal">true</span>) {
    <span class="hljs-comment">// If we didn&apos;t find anything, let&apos;s try the next sibling.</span>
    <span class="hljs-keyword">while</span> (node.sibling === <span class="hljs-literal">null</span>) {
      <span class="hljs-keyword">if</span> (node.return === <span class="hljs-literal">null</span> || isHostParent(node.return)) {
        <span class="hljs-keyword">return</span> <span class="hljs-literal">null</span>
      }
      node = node.return
    }
    node.sibling.return = node.return
    node = node.sibling
    <span class="hljs-keyword">while</span> (node.tag !== HostComponent &amp;&amp; node.tag !== HostText) {
      <span class="hljs-keyword">if</span> (node.effectTag &amp; Placement) {
        <span class="hljs-comment">// If we don&apos;t have a child, try the siblings instead.</span>
        <span class="hljs-keyword">continue</span> siblings
      }
      <span class="hljs-keyword">if</span> (node.child === <span class="hljs-literal">null</span> || node.tag === HostPortal) {
        <span class="hljs-keyword">continue</span> siblings
      } <span class="hljs-keyword">else</span> {
        node.child.return = node
        node = node.child
      }
    }
    <span class="hljs-keyword">if</span> (!(node.effectTag &amp; Placement)) {
      <span class="hljs-comment">// Found it!</span>
      <span class="hljs-keyword">return</span> node.stateNode
    }
  }
}</code></pre>
<p>&#x8FD9;&#x4E2A;&#x65B9;&#x6CD5;&#x7528;&#x6765;&#x627E;&#x5230;<strong>&#x5F53;&#x524D;&#x8981;&#x6267;&#x884C;&#x63D2;&#x5165;&#x7684;&#x8282;&#x70B9;&#x7684;&#x73B0;&#x6709;&#x7684;&#x7B2C;&#x4E00;&#x4E2A;&#x53F3;&#x4FA7;&#x8282;&#x70B9;&#xFF0C;&#x5982;&#x679C;&#x8FD9;&#x4E2A;&#x65B9;&#x6CD5;&#x8FD4;&#x56DE;<code>null</code>&#xFF0C;&#x5219;&#x4F1A;&#x76F4;&#x63A5;&#x8C03;&#x7528;<code>parent.appendChild</code></strong></p><p>&#x8FD9;&#x91CC;&#x4E3B;&#x8981;&#x8003;&#x8651;&#x7684;&#x95EE;&#x9898;&#x662F;<code>parent.appendChild</code>&#x662F;&#x63D2;&#x5165;&#x5230;&#x6700;&#x540E;&#x7684;&#xFF0C;&#x800C;&#x5BF9;&#x4E8E; React &#x7684;&#x8282;&#x70B9;&#x64CD;&#x4F5C;&#xFF0C;&#x5F88;&#x53EF;&#x80FD;&#x63D2;&#x5165;&#x7684;&#x8282;&#x70B9;&#x662F;&#x5728;&#x4E2D;&#x95F4;&#x3002;&#x5BF9;&#x4E8E;&#x7B2C;&#x4E00;&#x6B21;&#x6E32;&#x67D3;&#xFF0C;&#x56E0;&#x4E3A;&#x6240;&#x6709;<code>HostComponent</code>&#x90FD;&#x662F;&#x9700;&#x8981;&#x63D2;&#x5165;&#x7684;&#xFF0C;&#x6240;&#x4EE5;&#x6309;&#x7167;&#x987A;&#x5E8F;<code>appendChild</code>&#x6CA1;&#x6709;&#x95EE;&#x9898;&#xFF0C;<strong>&#x6240;&#x4EE5; React &#x628A;&#x8FD9;&#x4E00;&#x6B65;&#x653E;&#x5728;<code>completeWork</code>&#x5C31;&#x505A;&#x4E86;</strong>&#x3002;&#x4F46;&#x662F;&#x5BF9;&#x4E8E;&#x540E;&#x7EED;&#x66F4;&#x65B0;&#x8FD9;&#x4E2A;&#x662F;&#x4E0D;&#x786E;&#x5B9A;&#x7684;&#xFF0C;&#x6240;&#x4EE5;&#x8981;&#x627E;&#x5230;&#x6574;&#x68F5;&#x6811;&#x4E2D;&#x6240;&#x6709;<code>HostComponent</code>&#x7684;&#x6811;&#x7ED3;&#x6784;&#x4E2D;&#x7684;&#x53F3;&#x4FA7;&#x8282;&#x70B9;&#x3002;</p><p>&#x8FD9;&#x4E2A;&#x8282;&#x70B9;&#x53EF;&#x80FD;&#x5B58;&#x5728;&#x4E8E;&#xFF1A;</p><ul><li>&#x7236;&#x94FE;&#x4E2D;&#x4EFB;&#x4E00;&#x8282;&#x70B9;&#x7684;&#x53F3;&#x4FA7;&#x8282;&#x70B9;&#x7684;&#x5B50;&#x6811;&#x4E2D;&#x7684;&#x7B2C;&#x4E00;&#x4E2A;<code>HostComponent</code>
</li>
<li>&#x4ED6;&#x7684;&#x53F3;&#x4FA7;&#x5144;&#x5F1F;&#x8282;&#x70B9;&#x6216;&#x8005;&#x5B50;&#x6811;&#x4E2D;&#x7684;&#x7B2C;&#x4E00;&#x4E2A;<code>HostComponent</code>
</li></ul>
<p>&#x8FD9;&#x4E2A;&#x7B97;&#x6CD5;&#x5C31;&#x662F;&#x7528;&#x6765;&#x5B9E;&#x73B0;&#x8FD9;&#x4E2A;&#x641C;&#x7D22;&#x8FC7;&#x7A0B;</p><hr><p>&#x63A5;&#x4E0B;&#x53BB;&#x5C31;&#x662F;&#x5BF9;&#x4E0D;&#x540C;&#x7684;&#x60C5;&#x51B5;&#x6267;&#x884C;&#x4E0D;&#x540C;&#x7684;&#x63D2;&#x5165;&#x64CD;&#x4F5C;</p><p>&#x5BF9;&#x4E8E;<code>HostPortal</code>&#x4E0D;&#x9700;&#x8981;&#x64CD;&#x4F5C;&#xFF0C;&#x56E0;&#x4E3A;&#x8FD9;&#x5176;&#x5B9E;&#x662F;&#x4ED6;&#x7684;&#x5B50;&#x8282;&#x70B9;&#x63D2;&#x5165;&#x5230;<code>HostPortal.containerInfo</code>&#x7684;&#x8FC7;&#x7A0B;&#x3002;</p><p>&#x540C;&#x65F6;&#x8FD9;&#x662F;&#x4E2A;&#x5FAA;&#x73AF;&#xFF0C;&#x8FD9;&#x4E2A;&#x8DDF;&#x5728;<code>completeWork</code>&#x91CC;<code>appendAllChindren</code>&#x4E00;&#x6837;&#xFF0C;&#x8981;&#x628A;&#x5F53;&#x524D;&#x7EC4;&#x4EF6;&#x7684;&#x7B2C;&#x4E00;&#x5C42;&#x5B50;&#x8282;&#x70B9;&#x6267;&#x884C;&#x63D2;&#x5165;&#xFF0C;&#x6BD4;&#x5982;&#x5F53;&#x524D;&#x7EC4;&#x4EF6;&#x5982;&#x679C;&#x662F;&#x4E00;&#x4E2A;&#x8FD4;&#x56DE;&#x6570;&#x7EC4;&#x7684;<code>ClassComponent</code></p></div><div class="api-method-code"><div class="api-method-sample" data-lang="js" data-name="JavaScript"><pre><code class="lang-js"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">commitPlacement</span>(<span class="hljs-params">finishedWork: Fiber</span>): <span class="hljs-title">void</span> </span>{
  <span class="hljs-keyword">if</span> (!supportsMutation) {
    <span class="hljs-keyword">return</span>
  }

  <span class="hljs-comment">// Recursively insert all host nodes into the parent.</span>
  <span class="hljs-keyword">const</span> parentFiber = getHostParentFiber(finishedWork)

  <span class="hljs-comment">// Note: these two variables *must* always be updated together.</span>
  <span class="hljs-keyword">let</span> parent
  <span class="hljs-keyword">let</span> isContainer

  <span class="hljs-keyword">switch</span> (parentFiber.tag) {
    <span class="hljs-keyword">case</span> HostComponent:
      parent = parentFiber.stateNode
      isContainer = <span class="hljs-literal">false</span>
      <span class="hljs-keyword">break</span>
    <span class="hljs-keyword">case</span> HostRoot:
      parent = parentFiber.stateNode.containerInfo
      isContainer = <span class="hljs-literal">true</span>
      <span class="hljs-keyword">break</span>
    <span class="hljs-keyword">case</span> HostPortal:
      parent = parentFiber.stateNode.containerInfo
      isContainer = <span class="hljs-literal">true</span>
      <span class="hljs-keyword">break</span>
    <span class="hljs-keyword">default</span>:
      invariant(
        <span class="hljs-literal">false</span>,
        <span class="hljs-string">&apos;Invalid host parent fiber. This error is likely caused by a bug &apos;</span> +
          <span class="hljs-string">&apos;in React. Please file an issue.&apos;</span>,
      )
  }
  <span class="hljs-keyword">if</span> (parentFiber.effectTag &amp; ContentReset) {
    <span class="hljs-comment">// Reset the text content of the parent before doing any insertions</span>
    resetTextContent(parent)
    <span class="hljs-comment">// Clear ContentReset from the effect tag</span>
    parentFiber.effectTag &amp;= ~ContentReset
  }

  <span class="hljs-keyword">const</span> before = getHostSibling(finishedWork)
  <span class="hljs-comment">// We only have the top Fiber that was inserted but we need recurse down its</span>
  <span class="hljs-comment">// children to find all the terminal nodes.</span>
  <span class="hljs-keyword">let</span> node: Fiber = finishedWork
  <span class="hljs-keyword">while</span> (<span class="hljs-literal">true</span>) {
    <span class="hljs-keyword">if</span> (node.tag === HostComponent || node.tag === HostText) {
      <span class="hljs-keyword">if</span> (before) {
        <span class="hljs-keyword">if</span> (isContainer) {
          insertInContainerBefore(parent, node.stateNode, before)
        } <span class="hljs-keyword">else</span> {
          insertBefore(parent, node.stateNode, before)
        }
      } <span class="hljs-keyword">else</span> {
        <span class="hljs-keyword">if</span> (isContainer) {
          appendChildToContainer(parent, node.stateNode)
        } <span class="hljs-keyword">else</span> {
          appendChild(parent, node.stateNode)
        }
      }
    } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (node.tag === HostPortal) {
      <span class="hljs-comment">// If the insertion itself is a portal, then we don&apos;t want to traverse</span>
      <span class="hljs-comment">// down its children. Instead, we&apos;ll get insertions from each child in</span>
      <span class="hljs-comment">// the portal directly.</span>
    } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (node.child !== <span class="hljs-literal">null</span>) {
      node.child.return = node
      node = node.child
      <span class="hljs-keyword">continue</span>
    }
    <span class="hljs-keyword">if</span> (node === finishedWork) {
      <span class="hljs-keyword">return</span>
    }
    <span class="hljs-keyword">while</span> (node.sibling === <span class="hljs-literal">null</span>) {
      <span class="hljs-keyword">if</span> (node.return === <span class="hljs-literal">null</span> || node.return === finishedWork) {
        <span class="hljs-keyword">return</span>
      }
      node = node.return
    }
    node.sibling.return = node.return
    node = node.sibling
  }
}</code></pre>
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